Those numbers in the brackets are precision and scale. See here: http://msdn.microsoft.com/en-us/library/ms187746.aspxIn plain English, You can have at most 11 digits in the number, of which 2 are reserved for the fractional part. The remaining 9 are available for the integer part.

In the example below, the first two are valid; the second will be rounded off to two decimal digits. But the 3rd will result in an overflow